Fastener products can be formed in a continuous process using an apparatus, which includes, among other things, a mold roll. Such mold rolls typically are comprised of multiple, thin plates that are stacked together. Along a circumferential surface of each plate molding surfaces are etched or otherwise formed within the plates. When the plates are aligned along a central axis, the molding surfaces of the plates cooperate with adjacent, flat plates to define very small molding cavities. These cavities are often hook-shaped. Generally, the fastening hooks are formed in the machine direction (i.e., the longitudinal direction of the resulting fastener product).
It is also possible to form fastener elements using an injection mold having multiple plates stacked together. Many of the plates cooperate with adjacent flat plates to define cavities. Unlike conventional mold rolls, conventional injection molding is a discrete shot molding process (i.e., a discontinuous linear movement).
To form fastener elements using a mold roll or injection mold, molten resin is forced into the cavities. The molten resin is then allowed to cool and harden while within the cavity. Finally, the hardened resin is stripped from the cavity exposing newly molded projections extending from a newly formed base.
Due to the configuration of plates in conventional mold rolls, it is much easier to mold fastener elements oriented in the machine direction (i.e., the longitudinal direction of the fastener product) than in other directions. However, fastener element heads overhanging in a cross-machine direction would be useful in some applications.
Conventional mold rolls are expensive, and damage to cavities within the conventional mold roll frequently results in costly repairs or even replacement of the entire mold roll. Due to the mold roll configuration, it is difficult and time-consuming to repair or replace the affected plate or plates.